// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Globalization;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Testing;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Logging.Testing;
using Xunit;

namespace Microsoft.AspNetCore.Mvc.ModelBinding.Binders
{
    public class SimpleTypeModelBinderTest
    {
        [Theory]
        [InlineData(null)]
        [InlineData("value")]
        [InlineData("intermediate   whitespace")]
        [InlineData("\t untrimmed whitespace \t\r\n")]
        public async Task BindModelAsync_ReturnsProvidedString(string value)
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(string));
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", value }
            };

            var binder = new SimpleTypeModelBinder(typeof(string), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.Same(value, bindingContext.Result.Model);
            Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
        }

        [Theory]
        [InlineData("")]
        [InlineData(" \t \r\n ")]
        public async Task BindModel_ReturnsProvidedWhitespaceString_WhenNotConvertEmptyStringToNull(string value)
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(string));
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", value }
            };

            var metadataProvider = new TestModelMetadataProvider();
            metadataProvider
                .ForType(typeof(string))
                .DisplayDetails(d => d.ConvertEmptyStringToNull = false);
            bindingContext.ModelMetadata = metadataProvider.GetMetadataForType(typeof(string));

            var binder = new SimpleTypeModelBinder(typeof(string), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.Same(value, bindingContext.Result.Model);
            Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
        }

        public static TheoryData<Type> ConvertibleTypeData
        {
            get
            {
                var data = new TheoryData<Type>
                {
                    typeof(byte),
                    typeof(short),
                    typeof(int),
                    typeof(long),
                    typeof(Guid),
                    typeof(double),
                    typeof(DayOfWeek),
                };

                // DateTimeOffset doesn't have a TypeConverter in Mono.
                if (!TestPlatformHelper.IsMono)
                {
                    data.Add(typeof(DateTimeOffset));
                }

                return data;
            }
        }

        [Theory]
        [MemberData(nameof(ConvertibleTypeData))]
        public async Task BindModel_ReturnsFailure_IfTypeCanBeConverted_AndConversionFails(Type destinationType)
        {
            // Arrange
            var bindingContext = GetBindingContext(destinationType);
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", "some-value" }
            };

            var binder = new SimpleTypeModelBinder(destinationType, NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.False(bindingContext.Result.IsModelSet);
        }

        [Theory]
        [MemberData(nameof(ConvertibleTypeData))]
        public async Task BindModel_CreatesError_WhenTypeConversionIsNull(Type destinationType)
        {
            // Arrange
            var bindingContext = GetBindingContext(destinationType);
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", string.Empty }
            };
            var binder = new SimpleTypeModelBinder(destinationType, NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.False(bindingContext.Result.IsModelSet);
            Assert.Null(bindingContext.Result.Model);

            var error = Assert.Single(bindingContext.ModelState["theModelName"].Errors);
            Assert.Equal("The value '' is invalid.", error.ErrorMessage, StringComparer.Ordinal);
            Assert.Null(error.Exception);
        }

        [Fact]
        public async Task BindModel_Error_FormatExceptionsTurnedIntoStringsInModelState()
        {
            // Arrange
            var message = "The value 'not an integer' is not valid.";
            var bindingContext = GetBindingContext(typeof(int));
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", "not an integer" }
            };

            var binder = new SimpleTypeModelBinder(typeof(int), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.False(bindingContext.Result.IsModelSet);
            Assert.Null(bindingContext.Result.Model);
            Assert.False(bindingContext.ModelState.IsValid);
            var error = Assert.Single(bindingContext.ModelState["theModelName"].Errors);
            Assert.Equal(message, error.ErrorMessage);
        }

        public static TheoryData<ModelMetadata> IntegerModelMetadataDataSet
        {
            get
            {
                var metadataProvider = new EmptyModelMetadataProvider();
                var method = typeof(MetadataClass).GetMethod(nameof(MetadataClass.IsLovely));
                var parameter = method.GetParameters()[0]; // IsLovely(int parameter)

                return new TheoryData<ModelMetadata>
                {
                    metadataProvider.GetMetadataForParameter(parameter),
                    metadataProvider.GetMetadataForProperty(typeof(MetadataClass), nameof(MetadataClass.Property)),
                    metadataProvider.GetMetadataForType(typeof(int)),
                };
            }
        }

        [Theory]
        [MemberData(nameof(IntegerModelMetadataDataSet))]
        public async Task BindModel_EmptyValueProviderResult_ReturnsFailedAndLogsSuccessfully(ModelMetadata metadata)
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(int));
            bindingContext.ModelMetadata = metadata;

            var sink = new TestSink();
            var loggerFactory = new TestLoggerFactory(sink, enabled: true);
            var binder = new SimpleTypeModelBinder(typeof(int), loggerFactory);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.Equal(ModelBindingResult.Failed(), bindingContext.Result);
            Assert.Empty(bindingContext.ModelState);
            Assert.Equal(2, sink.Writes.Count());
        }

        [Theory]
        [InlineData("")]
        [InlineData(" \t \r\n ")]
        public async Task BindModel_ReturnsNull_IfTrimmedValueIsEmptyString(object value)
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(string));
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", value }
            };

            var binder = new SimpleTypeModelBinder(typeof(string), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.Null(bindingContext.Result.Model);
            Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
        }

        [Fact]
        public async Task BindModel_NullableIntegerValueProviderResult_ReturnsModel()
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(int?));
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", "12" }
            };

            var binder = new SimpleTypeModelBinder(typeof(int?), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.True(bindingContext.Result.IsModelSet);
            Assert.Equal(12, bindingContext.Result.Model);
            Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
        }

        [Fact]
        public async Task BindModel_NullableDoubleValueProviderResult_ReturnsModel()
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(double?));
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", "12.5" }
            };

            var binder = new SimpleTypeModelBinder(typeof(double?), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.True(bindingContext.Result.IsModelSet);
            Assert.Equal(12.5, bindingContext.Result.Model);
            Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
        }

        [Theory]
        [MemberData(nameof(IntegerModelMetadataDataSet))]
        public async Task BindModel_ValidValueProviderResult_ReturnsModelAndLogsSuccessfully(ModelMetadata metadata)
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(int));
            bindingContext.ModelMetadata = metadata;
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", "42" }
            };

            var sink = new TestSink();
            var loggerFactory = new TestLoggerFactory(sink, enabled: true);
            var binder = new SimpleTypeModelBinder(typeof(int), loggerFactory);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.True(bindingContext.Result.IsModelSet);
            Assert.Equal(42, bindingContext.Result.Model);
            Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
            Assert.Equal(2, sink.Writes.Count());
        }

        public static TheoryData<Type> BiggerNumericTypes
        {
            get
            {
                // Data set does not include bool, byte, sbyte, or char because they do not need thousands separators.
                return new TheoryData<Type>
                {
                    typeof(decimal),
                    typeof(double),
                    typeof(float),
                    typeof(int),
                    typeof(long),
                    typeof(short),
                    typeof(uint),
                    typeof(ulong),
                    typeof(ushort),
                };
            }
        }

        [Theory]
        [MemberData(nameof(BiggerNumericTypes))]
        public async Task BindModel_ThousandsSeparators_LeadToErrors(Type type)
        {
            // Arrange
            var bindingContext = GetBindingContext(type);
            bindingContext.ValueProvider = new SimpleValueProvider(new CultureInfo("en-GB"))
            {
                { "theModelName", "32,000" }
            };

            var binder = new SimpleTypeModelBinder(type, NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.False(bindingContext.Result.IsModelSet);

            var entry = Assert.Single(bindingContext.ModelState);
            Assert.Equal("theModelName", entry.Key);
            Assert.Equal("32,000", entry.Value.AttemptedValue);
            Assert.Equal(ModelValidationState.Invalid, entry.Value.ValidationState);

            var error = Assert.Single(entry.Value.Errors);
            Assert.Equal("The value '32,000' is not valid.", error.ErrorMessage);
            Assert.Null(error.Exception);
        }

        [Fact]
        public async Task BindModel_ValidValueProviderResultWithProvidedCulture_ReturnsModel()
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(decimal));
            bindingContext.ValueProvider = new SimpleValueProvider(new CultureInfo("fr-FR"))
            {
                { "theModelName", "12,5" }
            };

            var binder = new SimpleTypeModelBinder(typeof(decimal), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.True(bindingContext.Result.IsModelSet);
            Assert.Equal(12.5M, bindingContext.Result.Model);
            Assert.True(bindingContext.ModelState.ContainsKey("theModelName"));
        }

        [Fact]
        public async Task BindModel_CreatesErrorForFormatException_ValueProviderResultWithInvalidCulture()
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(decimal));
            bindingContext.ValueProvider = new SimpleValueProvider(new CultureInfo("en-GB"))
            {
                { "theModelName", "12,5" }
            };

            var binder = new SimpleTypeModelBinder(typeof(decimal), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.False(bindingContext.Result.IsModelSet);
            Assert.Null(bindingContext.Result.Model);

            var error = Assert.Single(bindingContext.ModelState["theModelName"].Errors);
            Assert.Equal("The value '12,5' is not valid.", error.ErrorMessage, StringComparer.Ordinal);
            Assert.Null(error.Exception);
        }

        [Fact]
        public async Task BindModel_BindsEnumModels_IfArrayElementIsStringKey()
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(IntEnum));
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", new object[] { "Value1" } }
            };

            var binder = new SimpleTypeModelBinder(typeof(IntEnum), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.True(bindingContext.Result.IsModelSet);
            var boundModel = Assert.IsType<IntEnum>(bindingContext.Result.Model);
            Assert.Equal(IntEnum.Value1, boundModel);
        }

        [Fact]
        public async Task BindModel_BindsEnumModels_IfArrayElementIsStringValue()
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(IntEnum));
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", new object[] { "1" } }
            };

            var binder = new SimpleTypeModelBinder(typeof(IntEnum), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.True(bindingContext.Result.IsModelSet);
            var boundModel = Assert.IsType<IntEnum>(bindingContext.Result.Model);
            Assert.Equal(IntEnum.Value1, boundModel);
        }

        public static TheoryData<string, int> EnumValues
        {
            get
            {
                return new TheoryData<string, int>
                {
                    { "0", 0 },
                    { "1", 1 },
                    { "13", 13 },
                    { "Value1", 1 },
                    { "Value1, Value2", 3 },
                    // These two values look like big integers but are treated as two separate enum values that are
                    // or'd together.
                    { "32,015", 47 },
                    { "32,128", 160 },
                };
            }
        }

        [Theory]
        [MemberData(nameof(EnumValues))]
        public async Task BindModel_BindsIntEnumModels(string flagsEnumValue, int expected)
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(IntEnum));
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", flagsEnumValue }
            };

            var binder = new SimpleTypeModelBinder(typeof(IntEnum), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.True(bindingContext.Result.IsModelSet);
            var boundModel = Assert.IsType<IntEnum>(bindingContext.Result.Model);
            Assert.Equal((IntEnum)expected, boundModel);
        }

        [Theory]
        [MemberData(nameof(EnumValues))]
        [InlineData("Value8, Value4", 12)]
        public async Task BindModel_BindsFlagsEnumModels(string flagsEnumValue, int expected)
        {
            // Arrange
            var bindingContext = GetBindingContext(typeof(FlagsEnum));
            bindingContext.ValueProvider = new SimpleValueProvider
            {
                { "theModelName", flagsEnumValue }
            };

            var binder = new SimpleTypeModelBinder(typeof(FlagsEnum), NullLoggerFactory.Instance);

            // Act
            await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.True(bindingContext.Result.IsModelSet);
            var boundModel = Assert.IsType<FlagsEnum>(bindingContext.Result.Model);
            Assert.Equal((FlagsEnum)expected, boundModel);
        }

        private static DefaultModelBindingContext GetBindingContext(Type modelType)
        {
            return new DefaultModelBindingContext
            {
                ModelMetadata = new EmptyModelMetadataProvider().GetMetadataForType(modelType),
                ModelName = "theModelName",
                ModelState = new ModelStateDictionary(),
                ValueProvider = new SimpleValueProvider() // empty
            };
        }

        private sealed class TestClass
        {
        }

        [Flags]
        private enum FlagsEnum
        {
            Value1 = 1,
            Value2 = 2,
            Value4 = 4,
            Value8 = 8,
        }

        private enum IntEnum
        {
            Value0 = 0,
            Value1 = 1,
            Value2 = 2,
            MaxValue = int.MaxValue
        }

        private class MetadataClass
        {
            public int Property { get; set; }

            public bool IsLovely(int parameter)
            {
                return true;
            }
        }
    }
}
